How was Karl Marx influenced by important changes occurring in society such as the industrial revolution and the French revolution?
While not opposing industrialization, as to do so would have been folly, Karl Marx did view the Industrial Revolution as furthering the alienation of the working classes from the society for which they labored. Industrialization, then, was simply another phase of the process that would ultimately result in the complete socialization of society (a bit of a tautological sentiment). The divisions between the owners of capital and those they exploited for the accumulation of wealth, power and privilege existed in pre-Industrial Revolution history, as Marx noted in his 1847 essay The Poverty of Philosophy. There he wrote that "[t]he hand-mill gives you society with the feudal lord; the steam-mill society with the industrial capitalist," meaning the net effect of the Industrial Revolution was the refinement of an evolutionary process already underway, a sentiment also articulated in his essay on The First Indian War of Independence 1857-1859:
“The bourgeois period of history has to create the material basis of the new world — on the one hand universal intercourse founded upon the mutual dependency of mankind, and the means of that intercourse; on the other hand the development of the productive powers of man and the transformation of material production into a scientific domination of natural agencies. Bourgeois industry and commerce create these material conditions of a new world in the same way as geological revolutions have created the surface of the earth. When a great social revolution shall have mastered the results of the bourgeois epoch, the market of the world and the modern powers of production, and subjected them to the common control of the most advanced peoples, then only will human progress cease to resemble that hideous, pagan idol, who would not drink the nectar but from the skulls of the slain.”
For Marx, industrialization was an essential phase in the evolution of humanity; he believed it was inevitable given the tireless pursuit of wealth characteristic of the owners of capital. The Industrial Revolution was regrettable to the extent that the proletariat continued to be exploited for the benefit of a few, but, to reference an old proverb, "you can't make an omelette without breaking a few eggs." Industrialization would, according to Marx, eventually undermine the very moneyed capitalists who currently profited from it.
With respect to the French Revolution, Marx again viewed this turbulent period in French history through the prism of evolutionary economic theory, with the failures of French revolutionaries to establish a truly egalitarian society merely representing a transitional phase in which bourgeois capitalism merely replaced feudalism. In The Eighteenth Brumaire of Louis Bonaparte, Marx noted that,
". . . just when they [the French revolutionaries] seem engaged in revolutionizing themselves and things, in creating something that has never yet existed, precisely in such periods of revolutionary crisis they anxiously conjure up the spirits of the past to their service and borrow from them names, battle cries and costumes in order to present the new scene of world history in this time-honored disguise and this borrowed language."
The French Revolution, according to Marx, was old wine in new bottles -- autocrats replacing autocrats -- but it did, as with the Industrial Revolution, represent a transformative period in European history. The chaos and excesses -- think Robespierre and the Reign of Terror -- of the early revolutionary period were hardly the stuff from which a more advanced and socially enlightened period could blossom. Society had still to continue its evolution toward a period when the means of production, an essential development for the sustenance of humanity, were no longer the providence of the moneyed elites, but rather the possession of the working classes without whom the means of production would grind to a halt anyway.
In conclusion, Marx viewed the Industrial Revolution as an evolutionary phase, while he viewed the French Revolution as an imperfect advance that was equally essential in fulfilling his prophecy regarding economic history.