The aim of the paper is to provide a presentation and evaluation of Kazimierz Twardowski's conception (1912) called 'Twardowski's general conception of products of actions'. Among the theses that belong to it are theses that make together 'the conception of nonpermanent products as events'. As for the conceptions which are based on Twardowski's general conception of products of actions, all but one belong to the logic of language and semiotics. They include his conception of meaning and, within its confines, his conception of proposition as the product of judgement. The presentation and evaluation of Twardowski's conception of products of actions often requires preparatory considerations of a purely ontological, epistemological and/or methodological character. A separate section is devoted entirely to some ontological problems of complexity with the question of 'empty' parts as the question in focus. Twardowski's conception of products of actions has to be seen as making a contribution to the research on the ontological foundations of philosophy of action and philosophy of mind. If the objections that have been raised against it are correct, the importance of its contribution to this research may be questioned . Such is e. g. the import of the objections raised against Twardowski's conception of meaning: while this conception seems at first sight to substantially widen our perspectives in respect of the ontic status of meanings, the corrections proposed as a result of its critical appraisal reduce all that can have a claim to originality to a variant of the thesis to the effect that meanings are defective in respect of ontic autonomy. The results presented in the paper have some bearing on the question of Twardowski's attitude towards psychologism, as well as his contribution to the battle against it. Twardowski's conception of products of actions is essentially connected also with some of his other ideas, including his views on existence (the connection involves the conception of proposition as the product of judgement, and the conception of content). It has been pointed out that as the content of an act of judgement Twardowski might have been indicating (inconsistently) both existence as such and (in the background as it were) the appropriate instances of existence. The summary of criticism which has been given in the last part of the paper calls for comparison with the prospects of developing an 'ontology of products of actions' on the basis of the views of other philosophers.
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