  Spinoza, though, because he denies freedom of the will, is more thorough than Descartes in his commitment to naturalism. This commitment makes the task Spinoza undertakes in the Ethics an even more dramatic revision of traditional understandings of the passions than that which Descartes produced. So Spinoza, even more than Descartes, is open to the sort of objection which traditional authors, those to whom it seems beyond question that human beings are outside nature, might raise: how can the full range of human psychological phenomena be produced by natural causes? For the argument of the Ethics to succeed, Spinoza must produce, first, an account of how human desires and emotions might be a part of nature as he has presented it in the Ethics and, second, a description of those human desires and emotions which is plausibly complex, that is, plausibly consistent with our experience of ourselves. The subsections which follow address these issues in turn. 