FOREPLAY

FOREWORD

The question of whether the objective truth is the property of human thought — is not a question of theory, but a practical one

Marx

There is nothing more practical than a good theory

Poincaré

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VII

VIII

IX

EPILOGUE

And so — it is within nature that everyone is inclined to expect the others to live according to his own discretion

Spinoza

No standpoint has an absolute and permanent validity

Mach

AFTERWORD