Where did this idea that you can't Tax a Tax come from?

In another thread daltonr asked "Where did this idea that you can't Tax a Tax come from?".

It seems to be a widely held conception and from what I can gather one that is not accurate.

So can any of you experts on the theory, philosophy and history of taxation cast any light on the question?

aj

If this doesnt belong here feel free to move it

I would have thought that a tax on goods and services should be levied on the value of the good/service, not value plus tax. A tax itself does not add to the value of a good or service (e.g. I paid €10k stamp duty on a €400k house, so the house is now worth €410k-not likely!), so why/how would you levy a tax on a tax?

Also, there appears to be an inconsistency between taxes: VRT is levied on the VAT inclusive price of a car, but stamp duty is levied on the ex-VAT value of a property.

Thats my 2c (2.21c including VAT )

... also, before you even buy the house or car, you're paying income tax, health levy and PRSI.

Fill the car up with fuel and you're paying at least 6 different taxes & levies!