Language In A Petri Dish: the scientific misunderstanding of signals

No sane person deliberately seeks to misinterpret messages or to incorporate falsehoods into their reasoning. We pay attention to symbols because the consequences of ignorance or misunderstanding can be disastrous. Driving through a red traffic signal is an act that thankfully almost all drivers wisely avoid. If we weren't careful about the ways that we use symbols — their meanings — then communication would quickly descend into incomprehensible babble. It really does matter how we use signs and for the most part we stick to the rules. But sometimes even scientists are sloppy. This post is about a very specific but widespread form of scientific sloppiness: the misattribution of symbol-use to cells and simple organisms. 

Symbol users act in extremely strange ways. On the basis of a simple sign — a word, a coloured light or an abstract scrawl — we can be led to engage in some of the most elaborate, sophisticated, and sometimes the most bizarre, behaviours. And perhaps the most bizarre thing of all, is that the sign itself can be formed from absolutely anything. That is the extraordinary power of symbols: we can use anything to symbolise anything else, so long as the people we are communicating with know the rule we are using.

Rule following is perhaps the most fundamental requirement of symbol use. If we do not know the rule, we cannot know how to respond. This is why only the most intelligent creatures are capable of using symbols — because only the most intelligent creatures are capable of using tools; of putting raw materials to uses for which they were never designed.

A very brief scan of current research within the biological sciences will be sufficient to demonstrate that talk of chemical "signalling" between organisms (and even between cells) is extremely common. And neuroscience is almost entirely committed to the conviction that neurons produce signals. In my experience the merest suggestion that such talk is mistaken is often regarded as tantamount to heresy, not because there are particularly compelling reasons for supporting such a view, but because there seem to be so few reasons against it. In other words, talk of biological signalling is simply a terminological habit or convenience that adds just a little glamour to terms that would otherwise be restricted to "stimuli" and "causal triggers".

I am sometimes asked whether I think it does any harm to talk of biological or neurological signalling. My usual response is to say that I’m not in a position to know. But a better response would be this: what good does it do to suggest that we can observe the rudiments of language in a petri dish? Since when was it wise for scientists to get it manifestly wrong about their philosophical foundations, and since when was it wise for philosophy to follow suit?