







































But the fact is that Spinoza is made a testing-point in modern philosophy, so that it may really be said: You 
are either a Spinozist or not a philosopher at all. —Georg Wilhelm Friedrich Hegel, Lectures on the History 
of Philosophy, 1825-1830

Aisthesis      Volume 8,  201722

Deus, sive Natura: Substance and Determinism in Spinoza’s 
Ethics

by Joshua DeJoy

 Baruch Spinoza’s posthumously published 
Ethics is one of the most influential and systematic 
works of modern philosophical thought. In it, he 
details his thoughts on various subjects, including 
substance, causal necessity, and determinism. 
Spinoza, through establishing that there is only one 
substance—namely, God/Nature—arrives at the 
conclusion that humans do not actually exercise 
free will, that our actions are determined. Spinoza 
begins with monism, establishes that God and 
Nature are identical, and then concludes from this 
that actions ostensibly chosen freely are actually 
determined by external causes. This conclusion, the 
process used to reach it, or both, are critiqued by 
different philosophers, including Jonathan Bennett 
and Georgi Plekhanov. Ultimately, while Spinoza’s 
monism relies on somewhat dubious or superfluous 
theological justifications and his determinism is 
insufficiently elaborated and suggests some dubious 
consequences, his argument is compelling and 
historically significant. While not perfect, Spinoza’s 
thoughts are a remarkable and systematic exposition 
of determinism that cannot be fully dismissed. 
This essay summarizes Spinoza’s arguments for a 
pantheistic monism and determinism, examines 
three critiques of Spinozism, and finally concludes 
by assessing Spinozism’s staying power today.
 Spinoza’s argument for determinism—indeed, 
his entire metaphysics—begins with monism, or the 
belief that the world is made up of one substance. 
To begin Part I of Ethics, he defines several terms, 
most crucially substance, “that which is in itself and 
is conceived through itself;” attribute, “that which 
the intellect perceives of substance as constituting 
its essence;” mode, “the affections of substance;” 

and God, “an absolutely infinite being” (Spinoza 
217). Spinoza also provides, at the beginning of 
Part I of his Ethics, several axioms that are self-
evident based on his definition of these preceding 
terms—for example: “All things that are, are either 
in themselves or in something else” (Spinoza 
217). Crucially, Spinoza’s Axiom 5 says, “Things 
which have nothing in common with each other 
cannot be understood through each other; that 
is, the conception of the one does not involve the 
conception of the other” (Spinoza 218). Based on 
the definition of substance, Spinoza arrives at Part 
I, Proposition 2—“Two substances having different 
attributes have nothing in common”—because 
the conception of one substance cannot involve 
the conception of another, and commonalities in 
attributes necessarily invoke multiple substances 
(Spinoza 218). Due to Proposition 2 and Axiom 5, 
Spinoza concludes, “When things have nothing in 
common, they cannot be the cause of the other” 
(Spinoza 218). Therefore, there cannot be more than 
one substance—substances must be conceived of in 
and of themselves, and invoking one substance as the 
cause of another violates this definition (Hampshire 
38). This single substance, according to philosopher 
Stuart Hampshire, “is therefore to be identified with 
Nature conceived as a whole or as the totality of 
things” (Hampshire 38). Spinoza thus establishes a 
monist view of reality made up of one substance.
 Along the way to establishing monism, 
Spinoza makes something of a detour to prove 
the existence of God (“or substance consisting of 
infinite attributes, each of which expresses eternal 
and infinite essence”), which reinforces his monism 
(Spinoza 222). Curiously, he begins with a version of 



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Aisthesis      Volume 8,  201723

the ontological argument developed by St. Anselm 
and employed in a modified form by René Descartes 
(Allison 59). This argument, however, especially 
its reliance on existence as a perfection (although 
Spinoza does not expressly state this part of the 
argument), was already discredited in Spinoza’s time 
(Allison 59). Spinoza’s real goal is to establish an 
identity between God and the “substance consisting 
of infinite attributes” (Spinoza 222), or between God 
and Nature, “with [N]ature considered as an infinite 
… and necessary system of universal laws” (Allison 
35). The practical effect of this position is to render 
the idea of God as a being incoherent and, in reality, 
reduce God to Nature, or “a demonstration of the 
nonexistence of God—at least of the God of the 
Judeo-Christian tradition” (Allison 60). This attack 
on the Judeo-Christian idea of God is somewhat 
concealed in the phrase Deus, sive Nature [God, or 
Nature] (Spinoza 321), which nevertheless shocked 
public opinion and was branded as heresy and 
pantheism (Hampshire 39). Other early modern 
philosophers saw in Spinoza’s philosophy a radical, 
even atheistic aim. George Berkeley, opposing 
Spinoza, said, “Spinoza [is] the great leader of our 
modern infidels, in whom are to be found many 
schemes … such as undermining religion under the 
pretence of vindicating and explaining it” (qtd. in 
Melzer 253, emphasis added). Similarly, Pierre Bayle 
claimed, “One calls Spinozist all those who hardly 
have any religion, and who do not hide this fact very 
much” (qtd. in Melzer 253, emphasis added).  Given 
the circumstances in which Spinoza wrote—he was 
excommunicated from the local Jewish community, 
attacked by both conservative theologians 
and Cartesians, and then Ethics was published 
posthumously and subsequently censored—an 
esoteric reading, through which one attempts to 
“read between the lines,” in this section in particular 
is warranted (Melzer xii; Nadler; Spinoza 213). 
Spinoza thus removes the personal qualities of God 
and reduces the God/Nature concept to an ordered 
Nature.
 Spinoza draws radical conclusions from his 
monist thesis that there exists a single substance, 
Nature, including the orderly determination of the 
universe and even human behavior. Part I, Proposition 
29, concludes, “Nothing in nature is contingent, but 
all things are from the necessity of the divine nature 

determined to exist and to act in a definite way” 
(Spinoza 234). Only substances are determined by 
themselves, and God/Nature is the only substance, 
so all other things must be determined, in the final 
analysis, by God/Nature—that is, by natural laws, 
without contingency (Spinoza 234). Everything 
within Nature is determined.  Will itself—divine or 
mortal—is constrained by this, and, according to 
Proposition 32, “cannot be said to be a free cause, but 
only a necessary or constrained cause” (Spinoza 235). 
The first corollary to this is the radical position “that 
God does not act from freedom of will” (Spinoza 
235). Humans are, of course, a part of Nature (and 
of nature), and are likewise constrained by the lack 
of “freedom of will.” It should be noted here that 
one of the results of Spinoza’s subversive pantheism, 
whereby God is more or less depersonalized, is that 
there is no Judeo-Christian God to protect humans’ 
free will, in part because the problem of theodicy 
is no longer an issue when God is constrained as 
much as he is in Spinoza’s philosophy. In Part III, 
Proposition 2, Spinoza causally collapses the mind 
and body—that is, he notes that they are both caused 
by God (or Nature)—and thereby removes a place 
for the will to exercise any independent role in 
determining human action (Spinoza 279). Human 
actions are now “completely explicable by purely 
physical laws and in terms of physical equilibrium 
and of the recent disturbances of this equilibrium” 
(Hampshire 129). We are thus left with humans 
governed by the laws of Nature, not by free will.
 Of course, not everyone will accept that 
human behavior is entirely law-governed and that 
humanity has no free will. Spinoza anticipates some 
objections to this deterministic position in Ethics, 
beginning with the fact that there was not, at the 
time, a scientific explanation of human behavior and 
that language suggests that humans have free will. 
The reliance on words that appear to describe free 
choice, especially in vernacular writing, proves an 
obstacle for acceptance of determinism, especially 
for non-philosophers. In the Scholium to Part III, 
Proposition 2, Spinoza dismisses discussions of 
the ordinary senses of the words “will,” “choice,” 
“judgment,” etc., as unscientific—the perceptions 
of these phenomena are undoubtedly real, but they 
describe something that does not meaningfully exist 
(Hampshire 129; Spinoza 280). One could also argue 



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that if humans’ actions are determined by natural 
laws, then a rigorous science of human behavior 
should be possible. In his own time, there was no 
science of human behavior in any proper sense of the 
term—psychology did not exist. Spinoza, in the same 
Scholium, seems to have faith that such a science 
would emerge and would be capable, in principle at 
least, of discovering laws of human behavior:

Again, no one knows in what way and by what 
means the mind can move body, or how many 
degrees of motion it can impart to body and 
with what speed it can cause it to move. Hence 
it follows that when men say that this or that 
action of the body arises from the mind which 
has command over the body, they do not know 
what they are saying, and are merely admitting, 
under a plausible cover of words, that they are 
ignorant of the true causes of that action and are 
not concerned to discover it (Spinoza 280).

Unfortunately, centuries after Spinoza’s death, 
humanity has yet to explain human actions by 
means of rigorous laws, although progress has 
arguably been made toward this end. Moreover, 
relying on the current ignorance of explanations for 
human behavior explained in physical, determined 
terms is a poor argument for drawing a priori lines 
of human ignorance (Hampshire 130-1). That said, 
a powerful challenge to this ever-upward, ever-
more-comprehensive march of science exists in the 
form of quantum mechanics and developments in 
mathematics regarding uncertainty: “In the last fifty 
years [prior to 1951], physicists have abandoned 
the more simply mechanical models as essential 
to all physical explanation, and have admitted vast 
complexities of structure of an unmechanical kind, 
not only in the study of the human brain, but in other 
branches of biology and physiology …” (Hampshire 
133). While it is difficult to say a priori that these 
difficulties are inherently impossible to overcome, 
they certainly provide a formidable challenge to 
the rational explanation of human behavior and 
therefore of Spinozist determinism.
 A second critique of Spinozist determinism, 
taken up by Jonathan Bennett, is aimed at Spinoza’s 
description of the psychological and social 
consequences of accepting determinism. In Part 
III, Proposition 48, Spinoza claims that if one, for 
example, hates Peter, but then considers that he is not 

the cause of the hatred, that the hatred toward and 
overall will diminish (Spinoza 302-3). As Bennett 
notes, this is not exactly how hatred works. Further 
explanation, which may cause one to consider 
causes other than Peter in one’s displeasure (say, for 
example, that Paul assisted or even prompted him) 
will not necessarily lessen one’s hatred toward Peter 
absolutely, but at most proportionally, as now the 
hatred directed toward Peter will be added to the 
new hatred directed toward Paul (Bennett 338). In 
other words, hatred is not a finite resource. Spinoza’s 
later, further-reaching conclusions, including 
that understanding the causes which make events 
necessary will allow the mind to exercise greater 
control over the emotions prompted by those events 
(in Part V, Proposition 6), are likewise dubious 
(Spinoza 367). Bennett notes that this is not how 
emotions work at all—at best, the emotions will 
change somewhat involuntarily, either from anger 
to frustration or from one target to another (namely, 
its causes): “When I think of Peter deterministically, 
much of my hate is redirected towards his ancestors 
and schoolteachers; I have as great a total amount of 
hate as before, and now it is harder to control because 
it is wide-ranging and unfocussed” (Bennett 339). 
These are admittedly pretty significant weaknesses 
in Spinoza’s arguments regarding the effects of 
accepting determinism in one’s interpersonal life. 
However, if Spinoza is wrong about the effects of 
determinism, that does not invalidate determinism. 
That said, if Spinozist philosophy has little practical 
effect and clearly not much of a positive practical 
effect, its utility is certainly put into question.
 A third, final, critique, one that is much 
friendlier to Spinoza than the two previous ones, 
is that of Russian Marxist philosopher Georgi 
Plekhanov, commonly called the Father of Russian 
Marxism, citing German materialist philosopher 
Ludwig Andreas von Feuerbach. Plekhanov notes 
that Feuerbach “made the subtle observation … that 
pantheism is a theological materialism, a negation 
of theology but as yet on a theological standpoint” 
(“Fundamental Problems,” emphasis in the original). 
Much of this theology in Spinoza’s Ethics seems 
contrived to avoid serious repercussions, as per an 
esoteric reading, but nevertheless the abstraction 
of Nature would be troubling to strict materialists 
like Feuerbach and Plekhanov (it should be noted 



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Aisthesis      Volume 8,  201725

here that Feuerbach was a non-dialectical or so-
called vulgar materialist, whereas Plekhanov was a 
dialectical materialist). Feuerbach’s main criticism of 
Spinozism is that “in it the sensible, anti-theological 
essence of Nature assumes the aspect of an abstract, 
metaphysical being” (qtd. in “Fundamental 
Problems”). Plekhanov, seeing Feuerbach as not 
just the bridge that Karl Marx and Friedrich Engels 
took to get from Hegelian idealism to dialectical 
materialism but also from Spinozist semi-
materialism to dialectical materialism, approved 
of Feuerbach removing Spinozism’s “theological 
pendant.” He notes with satisfaction that “it was 
from the standpoint of this kind of Spinozism, which 
Feuerbach had freed of its theological pendant, 
that Marx and Engels adopted when they broke 
with idealism. … Consequently, the Spinozism of 
Marx and Engels was indeed materialism brought 
up to date (“Fundamental Problems,” emphasis in 
the original). Spinozist determinism still stands 
without the backing of God or an abstracted Nature. 
Plekhanov himself argued something very similar 
in another article, in which he notes “freedom 
[of the will] is merely necessity transformed into 
mind” (“The Role” 12). That is, by understanding 
that one’s actions are historically conditioned and 
“an inevitable link in the chain of inevitable events,” 
many are able to summon an indomitable will (“The 
Role” 12). This is similar to Spinoza’s collapsing of 
the body and mind in terms of causation of human 
actions. Plekhanov, because he understood Spinoza 
as the product of his time and as an advancement 
philosophically, conducted a friendly criticism in his 
discussion of philosophical developments, and even 
after this criticism, Spinozist determinism stands. 
Indeed, despite the aforementioned three critiques, 
it is clear that Spinozism has some staying power 
and, if nothing else, importance in the history of the 
development of human thought.
 Spinoza’s Ethics provides a comprehensive 
metaphysical discussion of the nature of the universe, 
causality, human actions, and morality. His work, 
which influenced philosophers as diverse as Hegel, 
Marx, Kant, Goethe, and Nietzsche, was considered 
dangerous enough that even the Dutch—along with 
the Catholic Church—censored it. By beginning 
with a metaphysical examination of substance, 
Spinoza puts forward for his famous “God, or 

Nature” formulation while establishing the universe 
as a monist substance capable of being rationally 
understood. He then proceeds to logically posit, 
although shockingly, that humans—and even God, 
to the extent that a personal God exists—do not have 
free will but are likewise law-governed and capable 
of being rationally understood. Recent challenges 
to Spinoza’s philosophy, especially the development 
of scientific thought in the intervening centuries, 
provide a challenge to his positions, especially 
determinism, although these are by no means 
definitively fatal. At any rate, one can still learn a 
great deal from Ethics and the debates surrounding 
it.

Works Cited
Allison, Henry E. Benedict de Spinoza: An 

Introduction. Rev. ed., Yale UP, 1987.
 

Bennett, Jonathan. A Study of Spinoza’s Ethics. 
Hackett, 1984.

Hampshire, Stuart. Spinoza. Penguin, 1951. 

Melzer, Arthur M. Philosophy between the Lines: 
The Lost History of Esoteric Writing. U of Chicago 
P, 2014.

Nadler, Steven. “Baruch Spinoza.” The Stanford 
Encyclopedia of Philosophy. Edited by Edward N. 
Zalta, Fall 2013 ed., Metaphysics Research Lab, 
Stanford University, 15 July 2013. Accessed 6 
Apr. 2016.

Plekhanov, Georgi. “Fundamental Problems of 
Marxism.” Selected Philosophical Works, vol. 3, 
Progress, 1976, pp. 117-83. Accessed 6 Apr. 2016. 

Plekhanov, Georgi. The Role of the Individual in 
History. International, 1940.

Spinoza, Baruch. Spinoza: Complete Works, 
translated by Samuel Shirley. Edited by Michael 
L. Morgan, Hackett, 2002.


