The simple answer is: Yes. You can.

[Ed: But you may find yourself tire quicker if you dont use a sight!]

However, in more depth, it depends on the circumstances. If you are aiming to shoot competitively then it depends on the tournament, the NFAA rules are quite strict on this matter.

If you are shooting a compound bow barebow style then the chances are you will not get away with using a sight anyway, so this is worth considering. If you can get more used to the bow without a sight then you are going to be a much more natural shooter than someone who has learnt only to use one.

With a sight, the arrow does not sit on your finger but on the sight itself. This may have some benefits it a tournament allows it but a lot of archers and of course hunters much prefer to not use one since it means the experience is much more solid.

Consider this; if you practice day in, day out with a sight and then try to shoot at a random distance, you will find it very, very hard to actually hit the target. However, if you practiced without using a sight then you would probably have a better gauge on the distance.

Tools and gadgets are all very well, but you shouldnt look at using something just because joe random does. Instead, consider what you want out of your sport or hobby. If you want to use a sight, then remember that you can almost always hit a static, same distance target better than an instict shooter. However, you may have to suffer if the distance changes just a few metres. There are pros and cons to any sport - know your limitations.