1. John Locke “On Human Understanding”

1. The objects of sensation one source of ideas.

2. Observable in children.

2. Rousseau "Emile"

1. Work or play are all one.

2. Teach your scholar to observe the phenomena of nature.

3. Kant: “Critique of Pure Reason"

1. Experience is itself a species of knowledge which involves understanding;

2. systematic unity is what first raises ordinary knowledge to the rank of science