How is error possible in mathematics?

Doubting everything and believing everything are two equally convenient solutions that guard us from having to think

Hypotheses are what we lack the least.

How is error possible in mathematics?

Mathematical discoveries, small or great are never born of spontaneous generation They always presuppose a soil seeded with preliminary knowledge and well prepared by labour, both conscious and subconscious.

Einstein does not remain attached to the classical principles, and when presented with a problem in physics he quickly envisages all of its possibilities. This leads immediately in his mind to the prediction of new phenomena which may one day be verified by experiment.

It is far better to foresee even without certainty than not to foresee at all.