Samanya Lakshana is one of the three kinds of extraordinary perceptions admitted by the Nyaya School. Besides samanyalakshana, the other two are jnana lakshana and yogaja. It is the perception of a whole class of objects through samanya (the generic property) perceived in any individual member of that class.
According to the Naiyayikas, when we perceive one pot we perceive the universal ‘potness’ as its defining property. It is the perception of the universal ‘potness’ in the present pot that serves the purpose of asathi, contact between sense and all other pots. The knowledge of the universal samanya jnana is here the medium of sense-object contact, by which we have the perception of all pots when one is perceived.
The Naiyayikas justify that is a type of real perception on the following grounds – without this type of extra-empirical contact, we cannot explain the knowledge of the universal propositions (vyapta) which is presupposed in inference. How do we know that all kinds of smoke are related to fire? If our perception is limited to a particular smokes, we cannot know this, for any number of particulars will not make up the universal. Hence we must admit that while perceiving one smoke, as related to fire, we perceive all smokes.
Again, without this contact, we cannot satisfactorily explain a negative judgment of perception like ‘This cloth is not a pot”, “This is not a cow”, and so on. To say that “This is not a cow” is to know the class of cows, i.e., all cows. This can be known only if, when perceiving one cow, we perceive all other cows through the universal ‘cowness’ as perceived in the present perceived cow. To be explicit: in samanya lakshana, the knowledge of the universal leads to the perception of the individual in which in inheres (asraya).