The "Spirit of the Age" is a German intellectual concept from a century ago. It is a term for the prevailing consensus of opinion of the current generation. Each generation tweaks and changes it to fit their beliefs; witness the radical difference in values between the 1950's and 1960's.
Each current generation is largely blind to the Spirit of their own age, while often displaying contempt for that of previous generations.
IF WE ARE BLIND TO IT, HOW CAN WE IDENTIFY THE SPIRIT OF OUR OWN AGE?
1. The Spirit of the Age is never defended or demonstrated by rational argument, it is assumed to be the only right way.
2. Anyone who speaks against the Spirit of the Age is not simply wrong, misguided or mistaken, they are BAD; as in EVIL.
3. Anyone who speaks against the Spirit of the Age must be vigorously defamed and their reputation publicly attacked.
4. It never occurs to the masses who blindly follow the Spirit of the Age that they use a hypocritical double-standard for judging the world.
For a practical demonstration, watch the news and see how anyone who disagrees with the status quo is treated.