Quote by Gottfried Wilhelm Leibniz: “Nothing is in the intellect that was not first in the senses, except the intellect itself.”

Leibniz challenges the purely empiricist view that all knowledge comes solely from sensory experience. While acknowledging sensory input, he argues that the mind itself possesses innate capacities and structures that process this information, meaning the intellect isn't a blank slate but an active participant in understanding.

This was a direct response and critique of John Locke's 'An Essay Concerning Human Understanding,' particularly Locke's concept of the mind as a tabula rasa (blank slate), central to the philosophical debates of the Enlightenment.

German polymath born in 1646 who made foundational contributions to mathematics, philosophy, and science. He developed calculus independently of Newton, and his philosophical system presented God, nature, and human experience as a pre-established harmony. His Theodicy attempted to reconcile divine goodness with the existence of evil.