from Don Garrett's review "All Necessarily So" of Steven Nadler's Spinoza's "Ethics": An introduction:
. . . the whole [Ethics] is arranged in a forbidding "geometrical order", an austere and magisterial structure of definitions, axioms, postulates, propositions, corollaries, demonstrations, and scholia modelled on Euclid's Elements. . . .
Spinoza was a necessitarian, holding that everything follows with absolute necessity from its equally necessary grounds or causes, in a way that leaves no room for contingency in nature. Nadler takes seriously the worry that the content of the Ethics therefore requires expression in its deductive geometrical format.
. . . many . . . have seen in Spinoza's monistic metaphysics - positing as it evidently does a single space-time entity whose local variations of forces, governed by pervasive natural laws, constitute physical "objects" as states of the universe rather than as component parts of it - a strikingly appropriate conceptual framework for contemporary physical theory. "Supersubstantivalism" , roughly the doctrine that space-time is the only substance and that physical objects are identifca; with regions or regionalized properties of it, is becoming something of a hot topic in contemporary metaphysics just now, and it is a view that obviously owes a good deal to Spinoza.
Similarly, Spinoza's account of the relation between the mental and the physical, which entails the identity of the human mind with the human body, was certainly provocative in its day . . . but it is equally so in our own. By treating the mental and the physical not simply as two different kinds of things or two different kinds of qualities, but instead as two fundamentally different dimensions of being that all things - with all their qualities - exemplify or express, Spinoza was a pioneer of "panpsychism", the doctrine that everything has some degree of mentality. . . . The attraction of panpsychism, as William James showed so vividly, lies partly in its compatibility with the kind of incremental naturalism that seeks to explain fundamental features of human thought - such as consciousness, representation and will - not as sudden and unpredictable interruptions in the course of nature but rather as sophisticated developments of features that pervade the naural world in a broad range of degrees, beginning with the very rudimentary.
Spinoza's ideas about freedom and responsibility are of comparable relevance and imporant to present-day philosophy. As Nadler emphazises, Spinoza's necessitarianism involved an unequivocal denial of free will, if having "free will" means that human beings can be causally undetermined in their voluntary behaviour. As Nadler also shows, Spinoza recognized and valued a different kind of freedom, a natural causal determination through one's own determined nature (rather than through external forces) that is attainable only in proportion to one's virtue.