Spinoza sought to bring the virtues of this method, so easily seen in the Elements , to bear in the field of philosophy. The branch of philosophy which studies the nature of the universe as a whole is metaphysics . The above is the label often attached to Spinoza's metaphysical system. What it means, in effect, is that fundamentally everything is one . The myriad of individual things which exist are dependent for their existence upon one substance .
Substance is then, of the three concepts mentioned above, the most fundamental.
In a certain sense, the concept of attribute contains both a metaphysical and an epistemological component the intellect perceives the essence of substance, or God, which is a certain attribute. The intellect is able to perceive God as having these two essential natures. Substance is prior in nature to its modifications, which means for Spinoza that a mode can neither be nor be conceived in itself and through itself. God exists necessarily, for it cannot be conceived otherwise, i.e., as not existing. God is both infinite and eternal, containing an infinite amount of modes, of which it is the cause.