There is absolutely nothing fair about a flat tax rate.  This world you envision where aristocrats inherit large estates tax free and then pay the same rate of income taxation as the pauper picking garbage down in the dump is many things but "fair" is certainly not one of them.  Apply your plan in our country and the result of your plan would be an increase in taxes for the poor and middle classes and a massive tax cut for the wealthiest Americans.  Again, many things, "fair" is not one of them.