What could Berkeley have said about Johnsons refutation?

Or he could have made up a load of new words.

Well... that wasn't very helpful. I wonder what are some pro-Berkeley counterarguments towards Johnsons refutation, if I wasn't clear.

Well what did you expect?

Dr. Johnson, failing to find any words to refute me, seemed to take his frustration out by scuffing his own shoe.

I can kick rocks in dreams (i.e., [sarcasm] what an astounding proof of the material world being metaphysical that Johnson had!). There would be little need for Berekley to bother responding to something that was so blatantly grounded in ignorance or misunderstanding, or even deliberate distortion of his ideas.

Any village arsehole can jump in front your face holding a green jar, proclaiming: "Here's the evidence that you buried your murdered aunt in the garden!" With you thinking: "I don't even have an aunt." Maybe a few minutes would be warranted in trying to straighten him out, but if after that he was still vehemently clinging to his own addled fantasy projected upon you, just call him a nut and walk on. Rather than wasting a couple of futile weeks that no more change his agenda or clear the fog in his head than the few minutes spent.

Johnson didn't refute Berkeley, largely because he obviously didn't understand Berkeley. Johnson thought that kicking a rock disproved Berkeley's rejection of the reality of matter because a rock is real and kicking it proves that it's real. But Berkeley, in rejecting matter, never said that everything is imaginary. Rather, he argued that we only experience things through our senses, and therefore it is only through sensation that we can know the world. Thus, to be is to be perceived (esse est percipi). Johnson perceives the rock to be real because he can see it and feel it. But in seeing and feeling the rock, Johnson isn't describing the rock (i.e. as a material thing), he's describing his perceptions of the rock (i.e. an idea).

Ok, this I understand. But what about Kant, would he respond the argument the same way?

JOHN STUART MILL = Matter, then, may be defined, a Permanent Possibility of Sensation. If I am asked, whether I believe in matter, I ask whether the questioner accepts this definition of it. If he does, I believe in matter: and so do all Berkeleians. In any other sense than this, I do not. But I affirm with confidence, that this conception of Matter includes the whole meaning attached to it by the common world, apart from philosophical, and sometimes from theological, theories. The reliance of mankind on the real existence of visible and tangible objects, means reliance on the reality and permanence of Possibilities of visual and tactile sensations, when no such sensations are actually experienced. <AN EXAMINATION OF SIR WILLIAM HAMILTON'S PHILOSOPHY>

IOW, one item to remember about philosophers of an idealist persuasion is that they were not immune to using words like "matter" and "material" in their own way. But such could range anywhere from meaning the corporeal phenomena of outer sense (empirical, observed bodies) to J S Mill's permanent possibilities of sensation. Rather than the terms referring to those extended entities being generalized as part of a metaphysical substance (or a hypothetical "stuff" composing them), which Berkeley criticized.

They could accept something akin to a "natural environment" of "material [extended] sensations" that indeed behaves independently of personal will and is inter-subjectively present in everyone's external perceptions. But they did not posit it or its physical character as being part of a transcendent version of "outside us", of it existing independently of all minds and the universal regularities of [outer] conscious experience (which exhibited world affairs).

Though again, the experienced environment was quite free of the arbitrary or lawless whims of a SINGLE intellect / perceiver like you or me. A human's personal wishes weren't going to defy gravity or enable survival from a direct gunpowder explosion, because the reality of external perception conformed to its own natural rules.

Well, Johnson wasn't trying to refute Kant - which is understandable, since Johnson was probably entirely unaware of Kant. Also, Kant didn't share Berkeley's version of idealism. Kant agreed that we can only experience the world through perception, but he didn't reject the concept of matter. Instead, he resorted to the notion of noumena to describe the indefinable essence of things.

Simply confined to what Kant thought of Berkeley's philosophy: There's some question as to whether Kant was correct in grouping Berkeley with the ancient Greek tradition, that the phenomenal world [outer sense world] should lack a status of "real" or was illusionary. Unless he was construing that from interpretations of passages in some of the bishop's later works. What I'm referring to will become more evident in the second quote below.

KANT = But these, and amongst them more particularly Berkeley, regarded space as a mere empirical presentation that, like the phenomenon it contains, is only known to us by means of experience or perception, together with its determinations. I, on the contrary, prove in the first place, that space (and also time, which Berkeley did not consider) and all its determinations a priori, can be known by us, because, no less than time, it inheres in our sensibility as a pure form before all perception or experience and makes all intuition of the same, and therefore all its phenomena, possible. It follows from this, that as truth rests on universal and necessary laws as its criteria, experience, according to Berkeley, can have no criteria of truth, because its phenomena (according to him) have nothing a priori at their foundation; whence it follows, that they are nothing but sheer illusion; whereas with us, space and time (in conjunction with the pure conceptions of the understanding) prescribe their law to all possible experience a priori, and at the same time afford the certain criterion for distinguishing truth from illusion therein. <PROLEGOMENA TO ANY FUTURE METAPHYSICS>

KANT = The dictum of all genuine idealists from the Eleatic school to Bishop Berkeley, is contained in this formula: "All cognition through the senses and experience is nothing but sheer illusion, and only, in the ideas of the pure understanding and reason there is truth."

The principle that throughout dominates and determines my Idealism, is on the contrary: "All cognition of things merely from pure understanding or pure reason is nothing but sheer illusion, and only in experience is there truth." <PROLEGOMENA TO ANY FUTURE METAPHYSICS>

KANT = I grant by all means that there are bodies without us, that is, things which, though quite unknown to us as to what they are in themselves, we yet know by the representations which their influence on our sensibility procures us, and which we call bodies, a term signifying merely the appearance of the thing which is unknown to us, but not therefore less actual. Can this be termed [traditional] idealism? It is the very contrary. <PROLEGOMENA TO ANY FUTURE METAPHYSICS>

KANT = By transcendental idealism I mean the doctrine that appearances are to be regarded as being, one and all, representations only, not things in themselves, and that time and space are therefore only sensible forms of our intuition, not determinations given as existing by themselves, nor conditions of objects viewed as things in themselves. <CRITQUE OF PURE REASON>

KANT = The expression, outside us, involves however an inevitable ambiguity, because it may signify either, something which, as a thing by itself, exists apart from us, or what belongs to outward appearance only. In order, therefore, to remove all uncertainty from that concept, taken in the latter meaning (which alone affects the psychological question as to the reality of our external intuition) we shall distinguish empirically external objects from those that may be called so in a transcendent sense, by calling the former simply things occurring in space.
[...]
Thus we see that all external perception proves immediately something real in space, or rather is that real itself. Empirical realism is therefore perfectly true, that is, something real in space always corresponds to our external intuitions. <CRITQUE OF PURE REASON>

Joe has come up with some good traditional answers for this.
In terms of where philosophy is now, dichotomies such as idealism versus materialism, or object-object distinctions are somewhat dated from the point of view of post-modernists such as Derrida, or pragmaticists such as Rorty (who reject the correspondence theory of truth, and a representationalist view of language). These developments have little significance in terms of everyday life in which "material objects" remains a useful concept, but the issue comes to the fore in areas such as cognitive science and even frontier physics where " the act of observation" itself becomes a focus for study. Note too that the word "refutation" itself may be a candidate for deconstruction (in Derrida's sense) or indeed from the non-philosophical point of view of alternative "logics".

TYPO:
....subject-object distinctions.....

[I enter the following without having read the above]:
WIthout subject-object distinctions not much would get done, yet does anyone think that such phenemena as the sound of fallen trees or the feel of broken tones would exist without mind (or that we call "mind")?

Well I can only speak in terms of Heidegger's Dasein which implies neither a mind, nor a body but a "state of being" which has Existenz as an integral part of social reality. That reality is characterized by "a potential world" by means of common language such that Dasein may or may not focus on (care for)agreed "objects" which are either "ready to hand" or "present at hand". Those objects have no ontological status outside the operation of Dasein within its parochial social realm.

As for "getting things done", this Heidegger proposes a separate realm of discourse from "being" in which "properties of objects" are either covertly agreed or negotiated. This leads to an existential account of "science", which cannot account for the fundamental level of "being".

Well, if by "traditional," you mean that I actually addressed the question rather than wandering off in a meandering digression atop my favorite hobby horse, then yes, I suppose I did give a traditional answer.

I see you have reverted to your unfortunate bolshy self. That was meant largely as a compliment which you have chosen to reject. If you consider more recent analysis of the idealism-materialism issue " a digression" that's your problem.
It really is about time you got rid of that chip on your shoulder about your lack of familiarity with modern philosophy.

None of this is needed. The OP wanted what Berkeley might have said. Berkeley wouldn't have talked about deflating any dichotomy or resorting to other logics to back his claim. That's modern philosophy speaking, not Berkeley.

Fine. Not one of us has the ability to talk for Berkeley because the zeitgeist/semantic backcloth has moved on. And according to Derrida, not even Berkeley himself could talk because even he would have moved beyond his original text ! I will leave it to the OP to decide whether that is a significant philosophical point or not.