“The only thing that we know is that we know nothing, and that is the highest flight of human wisdom.”

“We can know only that we know nothing. And that is the highest degree of human wisdom.”

“Nothing has been discovered, nothing has been invented. We can only know that we know nothing. And that's the highest degree of human wisdom.”

“All we can know is that we know nothing. And that's the height of human wisdom.”

“No sense of the irony of human experience, that we are the highest form of life on earth, and yet ineffably sad because we know what no other animal knows, that we must die.”

“The delight we take in our senses is an implicit desire to know the ultimate reason for things, the highest cause. The desire for wisdom that philosophy etymologically is is a desire for the highest or divine causes. Philosophy culminates in theology. All other knowledge contains the seeds of contemplation of the divine.”