“Those who are in ideology believe themselves by definition outside ideology: one of the effects of ideology is the practical denegation of the ideological character of ideology by ideology: ideology never says, ‘I am ideological’. It is necessary to be outside ideology, i. e. in scientific knowledge, to be able to say: I am in ideology (a quite exceptional case) or (the general case): I was in ideology. As is well known, the accusation of being in ideology only applies to others, never to oneself (unless one is really a Spinozist or a Marxist, which, in this matter, is to be exactly the same thing). Which amounts to saying that ideology has no outside (for itself), but at the same time that it is nothing but outside”

for science and reality
Source: Lenin and Philosophy and Other Essays (1968), "Ideology and Ideological State Apparatuses", p. 118