TITLE: "Probability" of a large integer being prime
QUESTION [5 upvotes]: Someone once told me (rather testily) that we cannot speak of the "probability that a number is prime" because the sequence is deterministic. I think I understood his point but would like to make sure. There is a theorem in Stopple's Primer of Analytic Number Theory (p. 97):

The probability that a large integer $N$ is prime is about $\dfrac{1}{\log N}$.

Of course, a large integer N is either prime or it is not. Its status is completely determined by its predecessors.
As long as we are careful to define the sample space, is there anything here that is controversial? Are there other probability-related objections to Stopple's theorem?
Thanks for any insight.
Edit: This was a pedagogical device, not a theorem, as the answers below (and Stopple) make clear.

REPLY [7 votes]: Speaking of the "probability that a number is prime" is less of a specific fact but more of a guiding principle. A lot of things can be quickly derived by applying this principle, and when a pleasing (alleged) fact is discovered, one can look for a more rigorous proof if one so desires.
As an example, consider computing the sum
$$ \sum_{p \leq n} \frac{1}{p}. $$
Applying the principle that a number $k$ is prime with probability $1 / \log k$, then the 'expected' value of the sum is 
$$ \sum_{p \leq n} \frac{1}{p} \approx \sum_{k = 2}^{n} \frac{1}{k \log k} 
\approx C_1 + \int_2^n \frac{dx}{x \log x} = C_2 + \log \log n $$
where $C_1$ and $C_2$ are some constants. This turns out to be the correct answer, in the sense that the difference of the two sides converges to $0$ if $C_2$ is chosen to be the Meissel-Mertens constant.