I have spoken to Einstein and he admitted to me that his theory was in fact no different from the one of Parmenides. Karl Popper More Quotes by Karl Popper More Quotes From Karl Popper I do not overlook the fact that there are irrationalists who love mankind, and that not all forms of irrationalism engender criminality. But I hold that he who teaches that not reason but love should rule opens up the way for those who rule by hate. (Socrates, I believe, saw something of this when he suggested that mistrust or hatred of argument is related to mistrust or hatred of man). Karl Popper hate men believe Reason like science, grows by way of mutual criticism; the only possible way of planning its growth is to develop those institutions that safeguard. the freedom of thought Karl Popper growth criticism way Piecemeal social engineering resembles physical engineering in regarding the ends as beyond the province of technology. Karl Popper engineering technology social [To] interpret Parmenides as a Kant before Kant ... this is exactly what we must do. Karl Popper It must be possible for an empirical system to be refuted by experience. Karl Popper experience The history of science, like the history of all human ideas, is a history of irresponsible dreams, of obstinacy, and of error. Karl Popper errors dream inspirational But some of these theories are so bold that they can clash with reality: they are the testable theories of science. And when they clash, then we know that there is a reality; something that can inform us that our ideas are mistaken. Karl Popper science reality ideas With regards to political enemies Plato had a kill-and-banish principle. ... In interpreting it , modern-day Platonists are clearly disturbed by it, even as they make elaborate attempts to defend Plato. Karl Popper political plato enemy [The aim of science is] to explain what so far has taken to be an explicans, such as a law of nature. The task of empirical science constantly renews itself. We may go on forever, proceeding to explanations of a higher and higher universality. Karl Popper taken law science Now this principle of induction cannot be a purely logical truth like a tautology or an analytic statement. . . . Karl Popper logical principles truth A system such as classical mechanics may be 'scientific' to any degree you like; but those who uphold it dogmatically - believing, perhaps, that it is their business to defend such a successful system against criticism as long as it is not conclusively disproved - are adopting the very reverse of that critical attitude which in my view is the proper one for the scientist. Karl Popper successful attitude believe We must plan for freedom, and not only for security, if for no other reason than that only freedom can make security secure. Karl Popper plan security freedom reason