Final answer:
John Locke is the philosopher who proposed that a child's mind is a 'tabula rasa' or blank slate, and that all knowledge comes from experience.
Step-by-step explanation:
The philosopher who viewed the child as a tabula rasa, or blank slate, in his developmental theory was John Locke. Locke believed that we are born without innate ideas, and that knowledge is instead determined only by experience derived from sense perception. This concept is essential within the realm of empiricism, the theory that the origin of all knowledge is sense experience.
Contrastingly, Jean Piaget's approach is known as the cognitive theory of development, focusing on cognitive processes through which knowledge is acquired. While Piaget and other thinkers like Ibn Sina and David Hume added depth to the understanding of cognitive development and empiricism, it was Locke who is most frequently associated with the idea of the mind as a blank slate.