[1]: III  It was dedicated “In memory of the countless men and women of all creeds or nations or races who fell victim to the fascist and communist belief in Inexorable Laws of Historical Destiny.” The title is a reference to Marx's book "The Poverty of Philosophy", itself a reference to Proudhon's book "The Philosophy of Poverty".

[2] Popper defines historicism as “an approach to the social sciences which assumes that historical prediction is their principal aim…”.

[1]: 3  He also remarks that “[t]he belief … that it is the task of the social sciences to lay bare the law of evolution of society in order to foretell its future… might be described as the central historicist doctrine.”[1]: 105–106 Popper distinguishes two main strands of historicism, a “pro-naturalistic” approach which “favours the application of the methods of physics”[1]: 2  and the “anti-naturalistic” approach which opposes these methods.

[3] Popper concludes by contrasting the antiquity of historicism (which, for example, Plato is said to have espoused) with the claims of modernity made by its twentieth-century adherents.

In other words: they are not laws; “a statement asserting the existence of a trend at a certain time and place would be a singular historical statement and not a universal law.”[1]: 115 In addition, given that historians are interested in the uniqueness of past events, it may be said that future events will possess a uniqueness that cannot be known in advance.

Indeed, this is the element which ultimately cannot be completely controlled by institutions (as Spinoza first saw); for every attempt at controlling it completely must lead to tyranny; which means, to the omnipotence of the human factor – the whims of a few men, or even one.”[1]: 158 Popper asserts that psychology cannot lead to a complete understanding of “the human factor” because “'human nature' varies considerably with the social institutions, and its study therefore presupposes an understanding of these institutions.”[1]: 158 IV) A law, natural (i.e. scientific) or social, may enable us to exclude the possibility of certain events but it does not allow us to narrow down the range of possible outcomes to only one.

Historical generalisations may be reduced to a set of laws of higher generality (i.e. one could say that history depends upon psychology).

Large scale social experiments cannot increase our knowledge of the social process because as power is centralised to enable theories to put into practice, dissent must be repressed, and so it is harder and harder to find out what people really think, and so whether the utopian experiment is working properly.

Popper concedes that historicism has an appeal as an antidote to the idea that history is shaped by the actions of "great men.

Small changes enable one to make limited, but testable and therefore falsifiable statements about the effect of social actions.

The Marxist philosopher Karel Kosík criticizes Popper's statement that "All knowledge, whether intuitive or discursive must be of abstract aspects, and we can never grasp the 'concrete structure of reality itself'.

"[8] Kosík also suggests that Popper and like-minded thinkers, including Ferdinand Gonseth of Dialectica[11] and Friedrich Hayek on The Counter-Revolution of Science,[12][8] lack an understanding of dialectical processes and how they form a totality.