The metaphysical doctrine of determinism simply asserts that all events in this world are fixed, or unalterable, or predetermined. It does not assert that they are known to anybody, or predictable by scientific means. But it asserts that the future is as little changeable as is the past. Everybody knows what we mean when we say that the past cannot be changed. It is in precisely the same sense that the future cannot be changed, according to metaphysical determinism.More Karl Raimund Popper quotes [03/29/2018 05:03:36]

Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society... then the tolerant will be destroyed, and tolerance with them... We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant.More Karl Raimund Popper quotes [03/29/2018 05:03:36]

No particular theory may ever be regarded as absolutely certain.... No scientific theory is sacrosanct...More Karl Raimund Popper quotes [03/29/2018 05:03:36]

But it is certainly not possible to insist on one hand that the formalism is complete and to insist on the other hand that its application to 'the actual' actually demands a step which cannot be derived from it.More Karl Raimund Popper quotes [03/29/2018 05:03:36]

To give a causal explanation of an event means to deduce a statement which describes it, using as premises of the deduction one or more universal laws, together with certain singular statements, the initial conditions ... We have thus two different kinds of statement, both of which are necessary ingredients of a complete causal explanation.More Karl Raimund Popper quotes [03/29/2018 05:03:36]