Seems like it would depend on what you see when you look out the window and if railings would interfere. And if your kids are liable to fall off the deck without railings being there. For toddlers an 8 inch drop could be a hazard. If this is a big deck and there are little kids or little dogs involved, a railing and locking gate might be useful as the deck could then be used as a playpen or corral, conveniently near the house.

I personally feel that a railing gives it more of a finished feel. Ours is about the same height and I left it sans railing for awhile but I felt as though it looked like a big slab of wood sitting there and ended up installing one. I used painted metal tube railings for ours. It's less conspicuous but still gives it a nice look and it was fairly easy to install once I got going.

As bboy mentioned, there's the safety issue as well if you have small children about. 8 inches isn't much to an adult but it would be to a toddler.

Toddlers often trip and fall over, have a crisis just toddling around on ordinary surfaces - without changes in elevation. So an 8 inch drop could be quite a hazard.

Instead of a railing, add a simple bench around the deck.