[archevel]

An organisation always has some kind of culture. If it is "defined" (I interpret that as something being written down) or not doesn't really matter. Whatever is defined in that sense is not really the culture of that organisation. You can define your culture in any way you want with whatever value statements you desire an organisation to embody, but most likely those will not reflect the actual culture in the org.

That's not to say that trying to be explicit with the culture you want in an organisation is bad. It is just recognising that the words are not the culture. The people, the way they interact and the atmosphere in the company and what drives it is what creates the company culture.