How do we define colonialism? Personally, I define it as an enforced takeover and subjugation of people by a distant power/empire. Would progress and change have occured in Africa without colonialism? Yes, through trade, exchange of ideas would have happened (e.g. a trading outpost had been set up in Delagoa Bay before the first Europeans, who were traders, came to KZN and started interacting with the Zulus, so even without Europeans in South Africa, Africans in South Africa would have been exposed to progress and technology and innovation). Would it have been peaceful and prosperous change? Probably not, because of the ethics and rules and politics that dominated societies in Africa. Traders, adventurers and settlers seeking escape from persecution elsewhere were not necessarily colonialists. Societies do not change and progress in a vacuum, but through exchange of ideas and interaction with other societies. Colonialism is  perhaps the most destructive way for this to happen?