The paper deals with two questions. The first question concerns the range of the 'mental picture' of a denoted object, created in the thought of a speaker. Classical (structural) linguistics and logical semantics concentrates on the essential features of the object (the necessary and sufficient conditions to reckon the object as a member of the considered class), whilst cognitive linguistics tends to treat all features associated with an object as valid for the mental picture of this object. The non-essential features are either stabilized by some linguistic facts (like derivations, proverbs, etc.), or are individually created in the text. The second question concerns the ontological character of the denoted objects. The object can be relatively ontologically independent, like: natural beings (e.g. plants, animals), some artefacts (e.g. buildings, tables), or the object can be an entity discernible by the human cognitive, linguistic categorization of the world (the parts of the body, some subsets or collections, the emotional states of a person). Some denoted objects can be human mental constructions (e.g. theoretical models, social ideologies). The ontological character of denoted objects seems to be essential in order to fix the 'tertium comparationis' in comparative research.