That which is asserted without proof can be dismissed without proof.

Scientists
Euclid
Ancient Greek mathematician active c. 300 BC. His Elements built geometry as a deductive system from axioms and definitions, creating the model of logical reasoning that has shaped mathematics and science for over two millennia.
View this figure's profile
Euclid's Other Quotes
Related Quotes
The five essential entrepreneurial skills for success are concentration, discrimination, organization, innovation and communication.
-- Michael Faraday
First, do no harm.
-- Hippocrates
Let food be thy medicine and medicine be thy food.
-- Hippocrates
Patience is bitter, but its fruit is sweet.
-- Hideyo Noguchi
Sometimes it is the people no one can imagine anything of who do the things no one can imagine.
-- Alan Turing
The laws of nature are but the mathematical thoughts of God.
-- Euclid