My two male cats fight pretty badly- please read details..?

They are about 2 years old and brothers. Not fixed- they never go outside so i FIGURED it wouldn't be a problem. Ill refer to them as #1 and #2- 1 is the one thats attacking #2 1 attacks him and hurts him badly and 2 is scared- ive never seen him this scared. I understand this is a dominance thing and number 1 is clearly the dominant cat- but is it wrong that i only punish #1 seeing that hes the one doing the attacking i spray him and not 2. Is this mean or unfair?