In fact, an entity with an infinite essence will, by definition, have infinite attributes. Spinoza builds upon the idea of an infinite God by going further and stating that absolutely infinite substance is indivisible. This is because, if it were divisible, and if each part would retain the nature of the infinite substance, which would result in there being more than one substance of the same nature, which Spinoza has already demonstrated is impossible. Moreover, if this substance were divisible in a way that meant that each part did not retain the nature of infinite substance that would result in the absolutely infinite substance ceasing to be. Because that is impossible, Spinoza comes to the conclusion that there can be no other substance but God.

If there can be no other substance but God, then extension and thought, if they exist, are either attributes of God or modes following from the attributes of God. Recalling that a substance can be a bearer of multiple attributes without being divisible, because an attribute is an essential property of substance and can be conceived through itself, it becomes clear that substances can have different attributes. Moreover, Spinoza suggests that the reality of a being goes parallel with its attributes. Therefore, an infinite being will have infinite attributes.

Examining Spinoza's reasoning about God, one sees further similarities between Leibniz and Spinoza. Spinoza comes to the conclusion that God cannot be conceived not to exist because existence is involved in his essence. Spinoza relies upon the principle of sufficient reason to come to the conclusion that there is always a cause for existence/non-existence. The only thing that could cause either God's existence or non-existence would have to be God. Leibniz also uses the principle of sufficient reasoning, but he uses it in a different manner. According to Leibniz, God is logically perfect, and, because he does not need anything else for his existence, nothing can prevent his existence.

Having established the existence of God, Spinoza goes on to look at what God would be described. He finds that God, as an infinite substance, cannot be bound by a finite body, shape, size, or extension. However, because God is the only substance, there cannot be corporeal bodies separate from God and created by God. If there is an extension, then it must be one of God's attributes, and therefore be infinite as well. Spinoza actually uses these propositions to declare that transcendent creation is possible, by establishing that substance cannot be produced or created from nothing, because existence is involved in its essence. Therefore, Spinoza rejects the transcendentalist approach. According to him, the main idea behind the transcendentalist approach is that corporeal substance is both finite and divisible, making it separate from God, who is both infinite and indivisible.

It is important to realize that their different conceptions of God mean that the philosophers also view morality in a very different manner. According to Spinoza God is the efficient cause of everything. He believes that intellect and will do not pertain to the nature of God. Instead, everything flows from God's nature, and not as a result of intellect or will. Therefore, God is not subject to any laws extrinsic to his own nature, including laws of morality. This point-of-view is very different than Leibniz's view, which suggests that even God's actions are guided by an overarching morality. Spinoza believes that intellect does not pertain to God's nature. If it did, it would be radically different from man's intellect, because God's intellect would necessarily come before those things of which he had knowledge, since God is prior in causality to all objects. If God's intellect was to be part of his nature, then it would not only be the cause of his essences, but also of the existences of things.

Spinoza's most difficult aspect of dealing with dualism comes when looking at the existence of finite things in the universe, if all things in the universe are extensions of God, who is, by definition, infinite. Spinoza comes to the conclusion that everything is determined by God's nature to exist and to exist in a determinate way. For him, there are two sides of Nature. First, there is the active, productive aspect of the universe, God and his attributes, from which all else follows. This side of Nature and God are identical. The other part of the universe is that which is produced and sustained by the active aspect. According to Spinoza, things could not have been produced by God in any other...

God does not act from free will. In fact, according to Spinoza, God has never made a decision. God is the necessary, infinite, indivisible material substratum of all things, but not the paternalistic decision-maker he is conceived of as being in some philosophies. In other words, nothing in nature is contingent; all things have been determined from the necessity of the divine nature to exist and produce an effect in a certain way.
However, there are differences in the way that these things depend upon God. Some features from the universe follow from the absolute nature of one of God's attributes in a direct and unmediated manner. These are the universal and eternal aspects of the world, which do not come into or go out of being: the infinite modes. The general laws of the universe are among those attribute: geometry, physics, and logic. However, some things are more remote from God. These things include particular and individual things. They are affections of God's attributes or modes by which God's attributes are expressed: they are finite modes.

According to Spinoza, there are two causal orders governing the production and actions of particular things. First, they are determined by the general laws of the universe that follow immediately from God's natures. However, each particular thing is determined to act and to be acted upon by other particular things. Therefore, the actual behavior of a body in motion is a function not just of the universal laws of motion, but also of the other bodies in motion and rest surrounding it and which it comes into contact. This may not be a causal relationship, but it does imply interconnectedness between particular things.

One of the challenges that Spinoza things mankind faces in its conception of God is due to teleological reasoning. Traditionally, people have anthropomorphized both God and nature. However, conceiving of God as having an intellect like a human's, denies the infinite nature of God. It is erroneous to assume that God does things for a certain purpose or to achieve a certain end. Spinoza believes that the anthropomorophization of God has led to serious misconceptions regarding normative and aesthetic standards. Teleological reasoning leads to instrumental reasoning, because when men are convinced that everything in nature was created for the sake of mankind, then they evaluate things according to the degree of usefulness for men. Therefore, man's conception of morality is based upon how useful things are for human.

When looking at the mind and the body, Spinoza views the body as a mode expressing a definite and determinate way of expressing some attributes of God's essence. Spinoza also views ideas as conceptions of the Mind. Speaking specifically of mankind, Spinoza notes that man is a thinking being. The mode of thought, such as emotions, feelings, and thoughts, require the idea of the object in question, but the idea is not always accompanied by the modes of though. Humans perceive only bodies and modes of thinking as individual things. Thought is an attribute of God; therefore God is a thinking being. Individual thoughts are, just like bodies are, expressions of God's essence in determinate and definite ways. Furthermore, Spinoza concludes that extension is an attribute of God, but scholars debate what it means to say that God has extension or is extended. Spinoza's idea that everything flows from God does not necessarily lead one to the conclusion that God is a pervasive spirit spread through all corporeal finite things. Instead, it could suggest that extended beings, as modes ontologically, causally, epistemologically, and conceptually dependent on God, are finite expressions of extension which is one infinite attribute of God.

Spinoza views the human mind as the idea of an individual actual thing (the human body), which is part of the infinite intellect of God. The perception of a certain thing by the human mind is equal to God, at least insofar as he is expressed by the human mind. Spinoza understood the human mind as the single but complex idea corresponding to the human body. Mind and body were mental and extended expressions of one and the same thing: the human person. Therefore, Spinoza rejects dualism. Instead, the human mind perceives whatever happens in the body, the object that corresponds to the idea constituting the mind. Therefore, he makes an explicit statement of mind-body union.

Therefore, the human mind, like God, contains ideas. Some of those ideas, like feelings, are imprecise qualitative phenomena, which…