Dissent?

In a free and open society like ours it is interesting how little genuine dissent there is. While I mean this in the specific sense of political discourse it has much broader ramifications you can ponder to yourself.

Not one of the three main political parties varies in their platforms. On the fundamental issues, that of governments role in society, that of how the system that is our nation should work, they are all in agreement. In a world of radical and broad opinion, the Canadian political discourse is one of tiny, almost minute degrees of difference between the parties in policies. A comma here, a decimal there; and yet people hold passionately to their view points and to their party loyalty...

Why is there no dissent in our media? Who drafts these policies and why do all the political parties adopt them? Why is there no alternative to what we have now? Indeed, the seemingly most progessive party the NDP is the most conservative! They want to maintain the system not only how it is but how it has been going.

Why is there no dissent?