To figure out what the acorn is - and also what the oak tree is - we have to observe the line of development from one to the other .
Observing an acorn on its own , we can never deduce that it is an oak tree .
To figure out what the oak tree is - and also what the oak tree is - we have to observe the line of development from one to the other .
Observing an acorn on its own , we can never deduce that it is an oak tree .