Is time merely an illusion?

I think this is a philosophical question rather than a scientific one, but apparently a famous scientist said the following:

Quote:

People like us, who believe in physics, know that the distinction between past, present and future is only a stubbornly persistent illusion.

(Albert Einstein)

It seems at once both completely ridiculous and also plausible. If true, I suppose it means that everything in the future is essentially predetermined (although that word presupposes time).