more advanced than some fish, that qualitative differences may restrict such statements to pretty gross contrasts between taxa that are quite clearly distinct in overall advancement. Nevertheless, if we could agree to it, the consequences of this simple conclusion would be significant. For example, we would not expect all vertebrates, from hagfish to chimpanzees, to be treated alike, as some of our present guidelines do.
The mere fact that such evaluations will be controversial does not excuse neglecting to put them forward in the scientific literature, where the rules of the game of debate and criticism are powerful tools. The best science is not limited to the most objective methods and hardest facts but adds to them extrapolations, judgments, and inductions. The late physical chemist Blaine Ramsey repeatedly expounded the importance of "enthusiastic tentativeness". Experienced observers using the methods of science can surely arrive at an approximation, with some validity, of the relative sophistication of communication by jungle drums and by a Shakespearean actor. Physicians routinely judge levels of consciousness, dividing it into a number of grades. Music teachers grade capacities in their domain--not fully agreeing with each other, but achieving some verifiability.
My hope is that at such conferences in the future we will not confine ourselves, each to his own animal and hard data, to the exclusion of fresh attempts to sum up estimates on comparisons of cognitive capacities. In order to show preliminary progress in the intrinsically exciting field of comparative cognition, and in particular in the task of recognizing the rightful place of dolphins, more workers are needed who will take up this challenge. Instead of confining arguments to one or two characters at a time, the broader, ethological experts will venture approximations as to several items from a longer list, some of them estimated objectively and others subjectively. It may be too much to expect 25 items or even 10 at first, but it is important to deal with as many as possible. At least we can see each hard won datum as part of a large agenda that has the potential of yielding reasonably scientific answers. If we do this with enthusiastic tentativeness and without excessive emotional attachment to our preliminary conclusions, this branch of science may be under way.
Comparative cognition is badly in need of an expanded base of information on the capacities of a variety of taxa, both for its intrinsic intellectual interest and because of urgent social pressures.
It is argued that the mental life, thought processes, consciousness and intelligence of nonhuman species are not all or none but graded over a very wide dynamic range in evolution as in ontogeny. The position is supported that these major domains of cognition are made up of a number of partly independent