Under intelligence I include any biological information systems within an organism. This is the perspective of the anthology “Evolutionary Epistemology” which spans evolved reactive behavior of bacteria thru intelligence of people. (Perhaps I should exclude some entirely internal information systems such as those devoted to the digestive system.)
I have in mind here to interpolate several stages in a purely speculative manner.
‘Epistemology’ ostensibly deals with beliefs. Behavior in support of survival depends on many things besides beliefs. Indeed beliefs are a very recent evolutionary phenomenon.
The most primitive behavior that I have heard of is the paramecium’s feeding strategy. The paramecium is generally propelling itself and is ‘aware’ of whether the density of sugar in its environment is decreasing. If so it chooses a new random direction. No memory is needed here—only a predicate and response both provided by DNA.
Pattern matching and instinctual or acquired responses to some patterns are often more important to survival than beliefs. In short conditioned responses are sometimes more important than rational behavior.
In the evolutionary history of intelligence I imagine a phase of simple pattern recognition where patterns are expressed in the genes that build neural machinery to detect the patterns. This is useless without concomitant responsive behavior to such patterns, either learned or innate. Later we evolved so that an organism could acquire new patterns during its lifetime. This led gradually to an ontology.
A much later stage is some natural form of predicate calculus which I assume evolved along side Chomsky’s innate grammar. This enables declarative knowledge. I can imagine an adaptive advantage for predicate calculus without language skill; I just suspect that they evolved together because the greatest value of such knowledge was bound up with communication.
A theory of mind arose more or less along side declarative knowledge. The minds of others were so important that special brain mechanisms and behavior arose to deal with them.
Hypothetical language which is broadly covered by the grammatical term ‘subjunctive’ presumably arose when we had built enough of a model of the world, including our conspecific creatures, to indulge in what-if. Closely aligned with this is what should be, what was, what might be, etc. Modal logic captures some of this imperfectly.