Mathematician:

1 is prime , 3 is prime, 5 is prime, 7 is prime, …. 11 is prime, so is 13 and therefore, by induction, all odd numbers are prime. QeD.

Physicist:

1 is prime, 3 is prime, 5 is prime, 7 is prime, 9 …. 11 is prime, 13 is prime, …. all odd numbers are prime, 9 is just experimental error.

Engineer:

1 is prime, 3 is prime, 5 is prime, 7 is prime, 9 is a good approximation, 11 is prime, 13 is prime, …. therefore, all odd numbers are prime.

Philosopher:

2 is the only prime number which is even, therefore we shall call it the “Odd Prime”