I always thought it was clear that Spinoza declared himself as a Pantheist. But apparently that is not the case and was argued, by his rivals, that he was a Pantheist.
http://plato.stanford.edu/entries/spinoza/For centuries, Spinoza has been regarded—by his enemies and his partisans, in the scholarly literature and the popular imagination—as a “pantheist”. It is not clear, however, that this is the proper way to look at his conception of God. Of course, Spinoza is not a traditional theist, for whom God is a transcendent being. But does Spinoza's identification of God with Nature mean that he is, as so many have insisted for so long, from the early eighteenth century up through the most recent edition of the Cambridge Dictionary of Philosophy, a pantheist?
In general, pantheism is the view that rejects the transcendence of God. According to the pantheist, God is, in some way, identical with the world. There may be aspects of God that are ontologically or epistemologically distinct from the world, but for pantheism this must not imply that God is essentially separate from the world. The pantheist is also likely to reject any kind of anthropomorphizing of God, or attributing to the deity psychological and moral characteristics modeled on human nature. The pantheist's God is (usually) not a personal God.
Within this general framework, it is possible to distinguish two varieties of pantheism. First, pantheism can be understood as the denial of any distinction whatsoever between God and the natural world and the assertion that God is in fact identical with everything that exists. “God is everything and everything is God.” On this view, God is the world and all its natural contents, and nothing distinct from them. This is reductive pantheism. Second, pantheism can be understood as asserting that God is distinct from the world and its natural contents but nonetheless contained or immanent within them, perhaps in the way in which water is contained in a saturated sponge. God is everything and everywhere, on this version, by virtue of being within everything. This is immanentist pantheism; it involves that claim that nature contains within itself, in addition to its natural elements, an immanent supernatural and divine element.
Is Spinoza, then, a pantheist? Any adequate analysis of Spinoza's identification of God and Nature will show clearly that Spinoza cannot be a pantheist in the second, immanentist sense. For Spinoza, there is nothing but Nature and its attributes and modes. And within Nature there can certainly be nothing that is supernatural. If Spinoza is seeking to eliminate anything, it is that which is above or beyond nature, which escapes the laws and processes of nature. But is he a pantheist in the first, reductive sense?
The issue of whether God is to be identified with the whole of Nature (i.e., Natura naturans and Natura naturata) or only a part of Nature (i.e., Natura naturans alone), which has occupied a good deal of the recent literature, might be seen as crucial to the question of Spinoza's alleged pantheism. After all, if pantheism is the view that God is everything, then Spinoza is a pantheist only if he identifies God with all of Nature. Indeed, this is exactly how the issue is often framed. Both those who believe that Spinoza is a pantheist and those who believe that he is not a pantheist focus on the question of whether God is to be identified with the whole of Nature, including the infinite and finite modes of Natura naturata, or only with substance and attributes (Natura naturans) but not the modes. Thus, it has been argued that Spinoza is not a pantheist, because God is to be identified only with substance and its attributes, the most universal, active causal principles of Nature, and not with any modes of substance. Other scholars have argued that Spinoza is a pantheist, just because he does identify God with the whole of nature.
However, this debate about the extent of Spinoza's identification of God with Nature is not really to the point when the question is about Spinoza's alleged pantheism. To be sure, if by ‘pantheism’ is meant the idea that God is everything, and if one reads Spinoza as saying that God is only Natura naturans, then Spinoza's God is not everything and consequently he is not a pantheist, at least in the ordinary sense. Finite things, on this reading, while caused by the eternal, necessary and active aspects of Nature, are not identical with God or substance, but rather are its effects. But this is not the interesting sense in which Spinoza is not a pantheist. For even if Spinoza does indeed identify God with the whole of Nature, it does not follow that Spinoza is a pantheist. The real issue is not what is the proper reading of the metaphysics of Spinoza's conception of God and its relationship to finite modes. On either interpretation, Spinoza's move is a naturalistic and reductive one. God is identical either with all of Nature or with only a part of Nature; for this reason, Spinoza shares something with the reductive pantheist. But and this is the important point—even the atheist can, without too much difficulty, admit that God is nothing but Nature. Reductive pantheism and atheism maintain extensionally equivalent ontologies.
Rather, the question of Spinoza's pantheism is really going to be answered on the psychological side of things, with regard to the proper attitude to take toward Deus sive Natura. And however one reads the relationship between God and Nature in Spinoza, it is a mistake to call him a pantheist in so far as pantheism is still a kind of religious theism. What really distinguishes the pantheist from the atheist is that the pantheist does not reject as inappropriate the religious psychological attitudes demanded by theism. Rather, the pantheist simply asserts that God—conceived as a being before which one is to adopt an attitude of worshipful awe—is or is in Nature. And nothing could be further from the spirit of Spinoza's philosophy. Spinoza does not believe that worshipful awe or reverence is an appropriate attitude to take before God or Nature. There is nothing holy or sacred about Nature, and it is certainly not the object of a religious experience. Instead, one should strive to understand God or Nature, with the kind of adequate or clear and distinct intellectual knowledge that reveals Nature's most important truths and shows how everything depends essentially and existentially on higher natural causes. The key to discovering and experiencing God, for Spinoza, is philosophy and science, not religious awe and worshipful submission. The latter give rise only to superstitious behavior and subservience to ecclesiastic authorities; the former leads to enlightenment, freedom and true blessedness (i.e., peace of mind).How delusional. Einstein accepted the notion of a Spinoza type God, but later on went on to say that he doesn't think he can call himself an pantheist. I wonder if there is some connection.