§72

The activity of looking for something in common between different samples in an ostensive definition given to you might be different in different cases.
(i) In the first case the person is told, "the colour you see in all these is called 'yellow ochre'". What are the distinctive features of this case?
 (a) The definite article is used (unlike (ii)).
 (b) The phrase 'the colour' is used which tells the person what kind of thing it is they are looking for.
 (c) The person might look at various colours and see that some of them are not featured in all of the samples - they could use a process of elimination.
(ii) In the second case the person is shown samples of various shapes all painted the same colour and told, "what these have in common is called 'yellow ochre'. In this case the person will most likely recognise that the common feature is not the shape given that the samples are various shapes. If the person is familiar with other colour terms they might well recognise that what they are looking for is 'yellow -[something]' and so be pointing in the direction of looking at the colour. Given that there are no other colours involved they won't go through the same kind of process of elimination as in (i).

What can we take from this?
Suggestions:
- That ostensive definitions might take various different forms.
- Perhaps it also draws attention to the idea of seeing-as.
- It could serve as a reminder of the fact that ostensive definitions can be variously interpreted.