the single-particle spectral function A ( k , ω ) specify the possible symmetries of the super- conducting state. The strength of the vertices in the different irreducible representations and the frequency dependence of the vertices are required to address quantitative questions about T$_{c}$ and its relationship to normal state properties. Calculation of these quantities is a forbidding prospect. Yet systematic understanding of factors determining T$_{c}$ appears possi- ble with a judicious combination of empirical information, phenomenology and microscopic theory. One may adopt contrasting attitudes towards the question of T$_{c}$ . One attitude is that it is a foolhardy task born of naiivete. After all, we cannot even calculate the correlation energy of the normal state of a metal or of liquid He $^{3}$, except by complicated numerical methods which are not our purview. Calculating the frequency and momentum dependence of vertices is even harder. The other attitude is that interesting issues arise in asking the question, and relating the answers to other measurable properties, and in examining the limit of validity of the answers. The second attitude is adopted here. This attitude is fostered by the enormous experimental and theoretical work on the e-ph problem on a wide variety of metals and the inter-relationship deduced in the various parameters determining their T$_{c}$ . In fact physical properties of the normal state of metals, for example the electronic effects on the phonon spectra, which depend on much more detailed understanding of e- ph interactions than T$_{c}$ , can be understood and calculated using controlled methods in agreement with experiments. The problem of e-e vertices is much harder. I will argue however that there is much to be learnt from the problem of e-ph interactions even for superconductivity due to e-e interactions. Also, there is a lot understood of the properties of the normal state of liquid He 3 through both measurements and calculations. We do have reliable deduction of a few Landau parameters for the whole range of Liquid He 3 densities and systematic attempts to calculate interaction vertices by constraining them by the measured Landau parameters and relating them to transport properties and the variations of T$_{c}$ with density [3]. For most metal of interest many more normal state properties are measurable in principle, and parameters fixing the essentials of the correlation functions of charge or spin or current correlations extracted. The quantitative question we shall be concerned about is the formulation of the model, the first aspect stated above, in terms of such quantities. Finally, it appears to be a fact that superconductivity of unconventional variety due to e-e interactions is present most often only in the region of the phase diagram of metals near 5