Final answer:
John Locke is the philosopher who believed that human nature is a blank slate at birth, and that all knowledge comes from experience, as explained in his work An Essay Concerning Human Understanding.
Step-by-step explanation:
The philosopher who taught that human nature is a blank slate at birth was John Locke. In his work An Essay Concerning Human Understanding, published in 1690, Locke posited that the human mind starts as a tabula rasa, or blank slate, and that all knowledge comes from experience. This experience is gathered through sensation and reflection, leading from simple to complex ideas. Locke's ideas laid the foundation for later philosophical discourse on human understanding and education.