A Fourier Transform doesn't provide information about the source components of the signal operated on, only its composition based on frequency and amplitude based on sine waves.
You can recover the result of adding the original source waveforms by adding the sine waves identified by the FT, but you can't use the FT to decide what the components looked like before they were added and resulted in the waveform upon which the FT is performed.
Nothing that doesn't use state information not part of the signal under analysis can recover the complex waveforms that might comprise the components added to make that signal.
For example, an FT used to deconstruct the complex sound of say, a trumpet and violin, being played at the same time will produce a set of sine waves of various frequencies and amplitudes, which when recombined produce the original signal. No listener could tell you whether the signal was produced by the two instruments, or by a set of sine waves as specified by the FT—that information is not in the signal.
You can recover the result of adding the original source waveforms by adding the sine waves identified by the FT, but you can't use the FT to decide what the components looked like before they were added and resulted in the waveform upon which the FT is performed.
Nothing that doesn't use state information not part of the signal under analysis can recover the complex waveforms that might comprise the components added to make that signal.
For example, an FT used to deconstruct the complex sound of say, a trumpet and violin, being played at the same time will produce a set of sine waves of various frequencies and amplitudes, which when recombined produce the original signal. No listener could tell you whether the signal was produced by the two instruments, or by a set of sine waves as specified by the FT—that information is not in the signal.