As might be expected, disappointments plague the theorist. Current scientific methods are so inadequate for the generation of theories that even those with true genius need to devote themselves to years of struggle and incessant experimental work. So many apparently immutable doctrines have fallen!

Basically, the theorist is a lazy person masquerading as a diligent one. He unconsciously obeys the law of minimum effort because it is easier to fashion a theory than to discover a phenomenon.

Let us emphasize again this obvious conclusion: A scholar's positive contribution is measured by the sum of the original data that he contributes. Hypotheses come and go but the data remain. Theories desert us, while data defend us. In short, the beginner should devote maximal effort to discovering original facts by making precise observations, carrying out useful experiments, and providing accurate descriptions. If, in spite of everything, he feels compelled to create vast scientific generalizations, let him do so later when the abundant observations he has reaped have earned him for a solid reputation. Then and only then will he be listened to with respect and discussed without ridicule. And if fortune smiles, he will someday wear the double crown of an investigator and philosopher.

Santiago Ramón y Cajal

The need for modeling in neuroscience is particularly intense because what most neuroscientists ultimately want to know about the brain is the model--that is, the laws governing the brain's information processing functions. In general, the model as a research tool is more important when the system under study is more complex.

There is no escaping this: imagine a neuroscientist assigned to fully describe the workings of a modern computer (which has only 1010 transistors to the brain's 1015 synapses). The investigator is allowed only to inject currents and measure voltages, even a million voltages at once, and then is told to simply think about what the data mean. The task is clearly impossible. Many levels of organization, from electron to web server, or from ion channel to consciousness--each governed by its own set of rules--lie between the end of the experimentalist's probe and a deep understanding of the abstract computing system at hand. A true understanding of the brain implies the capacity to build a working replica in any medium that can incorporate the same principles of operation-silicon wafers, strands of DNA, computer programs or even plumbing fixtures. This highly elevated 'practioner's' form of understanding must be our ultimate goal, since it will not only allow us to explain the brain's current form and function, but will help us to fix broken brains, or build better brains, or adapt the brain to altogether different uses.

Bartlett W. Mel