Under which specific (formal) conditions can I apply the superposition theorem?

Superposition theorem fails when you have two ideal (identical) voltage sources in parallel. Under which specific constraints can I apply it?

I have read that, in DC Circuits, superposition requires that ideal voltage sources are never placed in parallel, and ideal current sources are never placed in series. Is this true?

I have tried to apply it to the following circuit, with R1 = 0.25 ohms, R2 = 0.32 ohms and V1 = V2 = 1.5V, but I'm getting absurd results: • So can you show us your work? – dirac16 Feb 21 at 21:47
• Also, your result. One version of the circuit should be with the V1 = 0V (turned off and thus replaced by a short-circuit). The other version is with V2 turned off and should yield an identical circuit since V1 = V2, except the polarities are in the opposite direction. Therefore, the currents in each version are identical but opposing and therefore when superimposed cancel out and equal zero. – DKNguyen Feb 21 at 21:51
• Superposition will work for this circuit...the circuit you provided as a schematic is not the same as what you described originally. Show us your work. – Elliot Alderson Feb 21 at 22:36