Meaning: The quote "Free speech is not to be regulated like diseased cattle and impure butter. The audience that hissed yesterday may applaud today, even for the same performance" by William O. Douglas, a former Associate Justice of the Supreme Court of the United States, encapsulates the essence of free speech and its inherent unpredictability. In this quote, Douglas vividly illustrates the dynamic and ever-changing nature of public opinion and the need to protect the freedom of expression without subjecting it to undue regulation.

The comparison of free speech to "diseased cattle and impure butter" highlights the absurdity of treating it as a commodity subject to strict regulation. By employing this metaphor, Douglas emphasizes the organic and uncontainable nature of free speech, which cannot be confined or controlled in the same manner as tangible goods. This serves as a powerful reminder of the unique and essential role that free speech plays in a democratic society.

Furthermore, the notion that "the audience that hissed yesterday may applaud today, even for the same performance" underscores the inherent unpredictability of public opinion. Douglas suggests that the reception of speech and ideas is not fixed or predetermined, and what may have been met with disdain or disapproval at one point in time can be embraced and celebrated at another. This acknowledgment of the fluidity of public sentiment speaks to the complexities and nuances of free speech, emphasizing the need to safeguard it against arbitrary restrictions based on transient reactions.

In a broader context, this quote resonates with ongoing debates and challenges surrounding free speech, particularly in the digital age. The rapid dissemination of information and the amplification of diverse voices through online platforms have intensified discussions about the boundaries and limitations of free expression. As opinions and attitudes can shift rapidly in the digital realm, Douglas's assertion serves as a timely reminder of the importance of preserving the unfettered exchange of ideas, even in the face of evolving societal norms and attitudes.

The quote also raises important questions about the role of government and institutions in safeguarding free speech. By cautioning against the regulation of free speech akin to diseased cattle and impure butter, Douglas highlights the dangers of heavy-handed censorship and the stifling of dissenting voices. Instead, he advocates for a framework that respects the inherently unpredictable nature of public discourse and allows for the open exchange of ideas, even those that may initially provoke controversy or opposition.

In conclusion, William O. Douglas's quote serves as a poignant reminder of the dynamic and unpredictable nature of free speech. By rejecting the notion of regulating speech as one would control tangible goods, and by highlighting the ever-shifting landscape of public opinion, Douglas underscores the need to protect and uphold the fundamental right to free expression. In a world marked by rapid change and diverse perspectives, his words continue to resonate, urging us to embrace the inherent unpredictability of free speech and to champion its preservation in all its forms.