Spinoza claims that nothing can be destroyed except by an external cause, a claim that he describes as self-evident. However to me it seems anything but. Plenty of things seem to destroy themselves, a fact that Spinoza was surely aware of. Clearly then Spinoza must have had something different in mind when made that claim. And thus to evaluate whether this claim can withstand serious scrutiny we must first attempt to understand it as Spinoza did.
The most charitable way of understanding this proposition is as claiming that there is nothing in the nature of a thing that can lead particular things of that kind to their own destruction, and thus that if particular things do seem to destroy themselves it must be because of outside causes, or at least causes that aren’t part of their essence. This is a reading that follows in part from the demonstration, where Spinoza says that if follows from the fact that “the definition of each thing affirms, but does not deny, the essence” (170). Now this might seem to imply just that the essence of each thing cannot contain facts that prevent its existence. However, the derivation of proposition 6 in the same section motivates treating not just contradictory facts as excluded from the nature of each thing, but any self-destructive tendency. There Spinoza argues that everything must strive to preserve its existence because it can’t contain any drive to end its existence, which he claims follows from the proposition in question. Obviously this claim does not follow from simply the absence of properties that would prevent the thing from existing in the first place, and so we must conclude that Spinoza intended something like the charitable reading presented here, otherwise many of the propositions following it would have false derivations.
Although this proposition in this form doesn’t appear necessarily false it still seems open to counter-examples. Many physical objects seem liable to self-destruct by nature, for example time bombs and isotopes with short half-lives. However Spinoza might be able to argue that in such cases these things have been put into a self-destructive state by external forces, and thus that it is not because of their essential properties that they are destroyed. Whether this response succeeds in a addressing the problem is hard to tell. It depends on what is and isn’t part of the essence of the object. Now earlier in the Ethics Spinoza seems to claim that only attributes constitute essence (Part 1 Definition 4) and that thought and extension are the only attributes we know of (Part 2 Propositions 1 and 2). This would imply in the case of a non-thinking thing, like the time bomb, that its essence is extension. But if that is what Spinoza means by essence here then his claim that nothing can be destroyed, except by an external cause, is vacuous. I can’t think of any way in which the essence of extension could be negated, most destruction simply spreads a thing out (making it, if anything, more extended). Thus bombs are free to blow themselves up, and things to fall apart by their nature, because none of these activities negate their essence, and hence none of them would be destruction.
This isn’t what Spinoza seems to mean here. By destruction he seems to mean what we ordinarily think of as destruction, which includes blowing up and falling apart. Thus it seems charitable to interpret Spinoza’s use of essence here in the more traditional sense, as the properties that are necessary to make a thing the kind of thing that it is. But then we are back to the previous problem, namely that we don’t have a definitive way of saying what does and doesn’t count as an essential property. For example, a time bomb that doesn’t detonate itself may be defective and thus fail to be a time bomb proper. And so we might be inclined to argue that self-destruction is an essential part of being a working time bomb. However, it is hard to get traction against Spinoza using this line of argument, since Spinoza hasn’t taken a stance on how to determine what is and isn’t an essential property of most objects, assuming that we give Spinoza the benefit of the doubt, and assume he would include in the essence of a thing more than extension and thought . This leaves him free to hold fast to proposition 4, and on the basis of it reject the idea that properties such as self-detonation can possibly belong to the essence of time bombs.
Thus to really press Spinoza on this issue it seems necessary to argue that attributes Spinoza himself admits are part of the essence of some thing can lead to its self-destruction. People then serve as a good example, since Spinoza has taken a position about what is in the nature of people and it seems clear that people do on occasion seek their own destruction. Of course Spinoza doesn’t deny that people do occasionally kill themselves. But he explains such choices by claiming that these situations arise when a person “is overcome by causes which are external to him and contrary to his nature.” (241) Thus such a person may be forced by external causes to destroy themselves, such as when threatened with some greater harm if they don’t, or because they are overcome by passions which are external to their essential nature of being rational beings. Certainly this covers most of the ordinary cases of self-destruction. However, there are rare situations in which people seem to rationally choose their own destruction in order to achieve some result that they value more highly than continued existence. Most frequently this occurs in cultures that place a high value on individual honor. Because of this emphasis on honor individuals may choose to kill themselves, usually in a ritual fashion, to avoid dishonor or to regain their honor. Such an act seems like a rational choice, and not a case in which the individual is overcome by something external.
One possible response to such a situation is to claim that it is external causes that force this choice on the individual, either the situation that takes away their honor or the society that values honor so highly. Although this might be one way out I do not think that it would be to Spinoza’s liking. To accept this resolution would be to make external forces the cause of every action, and thus to deny that people ever have the possibility to be self-determined, or, in Spinoza’s terms, free. This is because every choice we make is in some sense presented to us by the situations in which we find ourselves. I can only choose to type these sentences because of certain external factors, namely my computer being on and in working condition. Spinoza of course avoids this possibility by arguing that people are the adequate causes of their choices, if they are rational, because that choice can be completely understood through their psychological state. This means that I am the cause of my writing, and not the state of my environment, because the fact that these sentences will be written follows from my current ideas and my rationality. And the same can be said about the individuals who kills themselves over personal honor; given their ideas about honor we can see that their self-destruction is the choice that they will make in order to do what they think is best.
A better response, and one available to Spinoza, is to claim that such individuals are indeed motivated by inadequate ideas, but in a form other than passions. Specifically it could be claimed that they have inadequate ideas about the value of honor. Since these ideas are inadequate they are not part of their essence, but rather something external to it. And so if these inadequate ideas move someone to destroy themselves it does not contradict the charitable understanding of the proposition presented here, which claimed only that things were not moved to self-destruction by their essential properties. Assuming that their ideas about honor really are inadequate this seems sound.
This response works only because we can claim that the value they placed on certain situations, namely being honorable, was caused by an inadequate idea of honor. But if any individual values anything other than their own survival then we can set up a similar situation, where they will be willing to risk a small chance of destruction in order to gain something of perceived value. And such risk taking would be a failure of endeavoring to preserve ones own being, which Spinoza says can only come about as a result of external causes. But Spinoza himself seems to highlight at least three things that seem rational to value: joy, pleasure, and freedom. And if we do value these things, based on an adequate ideas about them, it would seem that we might rationally accept an additional small risk of destruction, such as crossing the street a few more times than is absolutely necessary, in order to secure them. But this is perhaps a misconstrual of Spinoza. Although he talks as if joy and pleasure and freedom were valuable in and of themselves his arguments for their value rest on their being beneficial to survival. Thus properly speaking we should value them only inasmuch as they promote our survival, and so it is impossible for situations to arise where we might rationally prioritize them over our survival to any extent. Whether such a life, living in a one floor house in the suburbs and avoiding leaving it by telecommuting and having everything delivered (one that prioritizes survival above all else), is actually satisfying I shall leave alone.
Thus Spinoza seems to have the resources with which to deal with possible counter-examples involving human self-destruction. But Spinoza has these resources because we have charitably assumed that if something is destroyed by something is not in its essence then it is destroyed by an external cause and because we have granted him the freedom to determine which properties are essential by fiat. However, the actual demonstration says that is the “definition of each thing” which “posits but does not deny the essence of the thing”. However, consider the definition of suicides, namely “those who kill themselves”. Clearly to be a suicide is to destroy yourself, so in the case of suicides, so defined, it would indeed seem that self-destruction is an essential property. And yet this definition does not deny their essence. And so it would seem that the definition of a thing can indeed contain elements that lead to the destruction of particular such things, and thus that these things are the cause of their own destruction. Now Spinoza might object to introducing suicides as a kind, such that the properties that suicides are defined as having aren’t essential to them, and hence aren’t internal causes of destruction, possibly because they are a sub-kind of people in general. However there are plenty of unstable subatomic elements that do seem unquestionably to be a kind, and which are defined by having a particular half-life (a particular average time to decay). Of course this doesn’t reveal a contradiction within Spinoza, he is free to deny that they are in fact kinds. But it leaves us with a choice between accepting the doctrine that nothing can be destroyed by an external cause or between accepting an understandable and practically useful division of the world into kinds of things. Given that choice I think we have good grounds for rejecting Spinoza’s position.